Method of installing propeller shaft struts



Jan. 8, 1952 E. KAMMRITZ I METHOD OF INSTALLING PROPELLER SHAFT STRUTSFiled Aug. 10, 1948 II III R m W m m fly B y W m w 0 Patented Jan. 8,1952 UNITED STATES PATENT OFFICE METHOD OF INSTALLING PROPELLER SHAFTSTRUTS Arthur Kammritz, East Hartford, Conn. Application August 10,1948, Serial No. 43,493

1 Claim.

This invention relate to method of installing a propeller shaft-strutand more particularly to such struts as are used on motorboats and thelike and extend from the keel thereof to support the propeller shaft atthe proper angle and provide a bearing therefor.

The installation of a propeller shaft in a motor boat has heretoforebeen extremely difficult when using the one-piece type of propellershaft strut, due to the fact that the shaft must be aligned exactly withthe bearing on the strut in order to prevent vibration of the propellershaft, due to misalignment, and subsequent damage to the bearings andother movable parts of the motor boat's power plant.

An object of this invention is to provide a propeller shaft strut whichmay be aligned with a previously installed propeller shaft and thensecured in position on the boat in such alignment, thereby making itunnecessary to align the propeller shaft angle to correspond with. theangle of the bearing on the propeller shaft strut as is necessary withthe one-piece type of strut.

A further object of this invention is to provide a propeller shaft strutwhich may be simply and quickly installed on the boat and which isadapted to receive various types of bearings in accordance with theparticular type of propeller shaft used.

A still further object of this invention is to provide a propeller shaftstrut which is simple in its construction, inexpensive to manufacture,and adapted to provide a rigid propeller guard to prevent damage to thepropeller of the boat from foreign objects floating on or submerged'inthe water.

Further objects and advantages of this invention will be more clearlyunderstood from the following description and from the accompanyingdrawings in which:

Fig. 1 is a side view of my improved propeller shaft strut illustratingthe manner in which it is attached to the keel of a boat.

Fig. 2 is an elevational side view of my improved strut illustrating themanner in which the strut is prepared for alignment with the shaft.

Fig. 3 is an elevational side view of my novel strut with the bearingattached thereto.

Fig. 4 is a sectional view thereof on line 44 of Fig. 3.

In the embodiment of the invention as shown in the drawings, my improvedpropeller strut preferably comprises a bracket 5 formed of asubstantially fiat plate and having an integral flange 6 formed at thetop thereof and perpendicular thereto and provided with a plurality ofholes I for attaching the bracket to the keel of a boat 8 with suitablebolts or screws 9.

I To form a support for the propeller shaft H], which extends from theengine of the boat through a stufiing box H, I provide a bearing 12having a propeller guard IZ-a extending downwardly therefrom and havingears l3-I3 extending upwardly therefrom to form a slot (4 therebetweenwhich is adapted to receive the end of the bracket 5 when the strut isfully assembled and in position on the boat as shown in Fig. 1. The ears|3l3 are provided with coaxial holes to receive bolts l5l5 for securingthe bracket therebetween as will hereinafter be described. The bearing[2 has an axial bore therein to receive a suitable bushing It in whichis rotatably positioned the propeller shaft l0.

To install my improved propeller shaft strut on a boat, the propellershaft [0 is first installed in the boat and the correct size of bushingHi to fit the said shaft is placed in the bearing l2 and secured thereinby means of a set screw [1. The bracket 5, which is made sufiicientlylong to extend below the propeller shaft when the flange thereon is heldagainst the keel of the boat, is

then held firmly against the keel in the desired position, with the flatsides of the blade extending fore and aft of the boat and the flange 6firmly positioned against the keel thereof. The bracket 5 will then bein a position such as shown in Fig. 2 wherein the bottom of the bracket5 extends below the top of propeller shaft l0. While in this positionand using the propeller shaft as a guide, a line is scribed on thebracket parallel to the said shaft. The bracket is then removed and asecond line I8, indicated by the dotted line in Fig. 2, is scribed onthe bracket exactly parallel to the first line scribed thereon and apredetermined distance above the said first line which is equal to thedistance between the top of the propeller shaft 10 and the bottom of theslot M. The bracket is then out along this line l8 and will appear asindicated in Fig. 3 wherein the bottom of the bracket is parallel to thepropeller shaft l0 when the said bracket is positioned against the keeland provides a positioning end surface for properly aligning the bearing12 with the propeller shaft.

The bearing I2 is then slipped over the propeller shaft Ill and movedalong the propeller shaft until the end of the bracket 5 is positionedin the notch l4 as shown in Fig. 3 wherein the bottom of the bracket 5is in engagement with the bottom of the notch H to thereby accuratelylocate the hearing at the proper angle. The

2,582,040 i Z Y the said ears and bracket.

It will thus be seen that by; providing, a propeller shaft strut whichis aligned with the propeller shaft prior to the installation of thestrut instead of having to align the propeller shaft with the strut, asis the case when using a onepiece strut, the angle of the propellershaft does not have to be too carefully determined and the installationof the strut is thereforeextremely facilitated. V

It will also be noted that my improved propeller shaft strut may beslightly modified, to accommodate the particular wishes of the boatowner without departing from the spirit of the invention.

I claim:

The method of installing a propeller strut bracket and a bearingtherefor, wherein the bearing includes a slot, the bottom of which isparallel to the-longitudinal axis ofthe, bearing which includes firstinstalling a propeller shaft in a boat and in the desired functioningposition and in angular relation to the bottom thereof, then marking aline on the strut bracket along said shaft as said bracket is held inposition against the bottom of the boat, then drawing a line parallel tothe said scribed line at a distance predetermined by the distancebetween the bottom of the slot and theinner face ofthe bearing from saidfirst line and cutting the bracket on said second line to produce astraight edge, then slipping the bearing member over said shaft,positioning. the bottom of the bearing slot against the straight edge ofthe bracket and rigidly securing said bearing to the bracket instraightedge contacting relation.

ARTHUR E. KAMMRITZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS List Mar. 17, 1925

